Competition today Mutualisms jigsaw Predation and Consumption next week Parasites and hosts Humans vs other species data exercise
Natural selection favors individuals that do not compete Drives niche differentiation, trait specialization and potentially species diversification Natural selection can cause character displacement in areas where overlap is high
Two species cannot occupy the exact same niche if they need the same resource Those species cannot coexist at stable constant populations a winner and loser will emerge Leads to local extinction of weaker competitor or shift to a different ecological niche
Resources are variable/limiting in an environment leads to more symmetric competition (both struggle) Species compete for multiple resources exclusion based on a single resource is too simple Complete niche overlap (test tube) is rare TAKE HOME: Greater overlap = greater competition
Overlapping species may alter resource use to minimize competition resource partitioning = division of resources Species whose niches only partly overlap coexist easier use the environment differently = niche differentiation evolve traits to use different/less overlapping resources = character displacement Co-existing species can overlap by using different forms of resources